Lewis Hamilton has paid tribute to an 'amazing friend' who helped the Formula One superstar train and look after Roscoe in the wake of the bulldog's tragic death.
The 12-year-old rescue dog was a constant companion of the Briton as he jetted around the racing circuit and had long been a fan-favourite both in the paddock and on social media.
But Hamilton made the heartbreaking decision last week to put his 'best friend' to sleep on Sunday night after the unwell dog had fallen into a coma days earlier after suffering from a second case of pneumonia.
The 40-year-old made the decision after Roscoe's heart had stopped, and although his rhythm had been restarted, he failed to come out of the coma.
Hamilton shared a poignant post sharing the sad news with fans, which prompted thousands of responses from around the globe.
But on Wednesday, the Ferrari star also opted to thank Kristin McMillan, who looked after both Roscoe and Hamilton's other bulldog Coco, who died in 2020, for much of their lives.
Lewis Hamilton has shared a special message for the dog trainer and 'amazing friend' who helped him care for Roscoe
The Formula One superstar previously shared that he had made the heartbreaking decision to put his dog to sleep
'I want you to take time to uplift my amazing friend Kirstin,' Hamilton implored of his 41.2million followers. 'She trained both Roscoe and Coco and treated them like family.
'She helped look after their health and it is really through her that Roscoe lived so long.
'While I was travelling, she would take care of him and loved him as if he was hers. She was there every day, all day. Even with a family and other dogs to look after, she never missed a day.
'We stood together when letting Roscoe go. I am so grateful to have had her in my life and Roscoe's life. There is nobody like you Kirstin. Thank you.'
McMillan was equally moved by the passing of the dog - who maintained a vegan diet like his high-profile owner - reposting a message written by social media account All On the Board which paid tribute to Roscoe.
The professional dog trainer had previously asked her followers to keep Roscoe in their prayers while he was on life support in the latter stages of his illness.
'I have no control over outcome, but have fervently done my part so that this dogs body has been kept strong & resilient,' she wrote in a message on her Instagram Story. 'In crisis, he is prepared.
'That's (because) as you guys know Lewis has always made his health priority. Pray that the hands & hearts of the doctors are guided, resourced, and pure.'
Hamilton paid tribute to Kirstin McMillan's work and support of both Roscoe and his other bulldog Coco
McMillan had previously called upon her followers to send their prayers to Roscoe as he battle with illness
The 40-year-old frequently posted sweet pictures of himself with Roscoe in between races
But the bulldog was also given special privileges in the paddock, accompanying Hamilton to a number of Grands Prix (pictured at Silverstone this year)
In April, McMillan had previously cared for Roscoe during a period when he was first diagnosed with pneumonia.
At the time, doctors treated the canine companion with a mixture of Eastern and Western medicine, with Roscoe is thought to have received acupuncture as part of his treatment.
Such was Roscoe's impact on the world of Formula One that a number of Hamilton's fellow drivers also shared messages of support.
Former Mercedes team-mate George Russell commented under Hamilton's post sharing the tragic news that he was 'sorry for your loss, mate', while current team-mate Charles Leclerc - who owns a long-haired Dachshund called Leo with his own substantial following - posted a heart emoji.
'We are all thinking of you Lewis. We will miss you Roscoe, RIP,' wrote Haas driver Esteban Ocon, while Ferrari, Mercedes, and McLaren all sent kind words to the Briton.
Hamilton will now have to compete just days after Roscoe's passing at this year's Singapore Grand Prix.
The Ferrari driver is still without a win this season and currently sits sixth in the drivers' standings on 121 points.